Two more defendants who are charged in cases involving their work at the Pennsylvania Turnpike Commission have been arraigned.

Former turnpike commission chief executive Joseph Brimmeier and former commission employee Melvin Shelton showed up Thursday at a suburban Harrisburg district judge's office to hear the charges against them.

Both were released on $100,000 unsecured bond.

Eight defendants were charged Wednesday. Most of the charges relate to what state prosecutors call a "pay to play" scheme for contract-hungry vendors.

Brimmeier allegedly helped ensure turnpike contracts were awarded to vendors who gave money to Democratic candidates. The grand jury says Shelton held himself out to be a labor relations specialist but acted more like a Democratic Party functionary.

Shelton declined comment. Brimmeier's lawyer says his client will be exonerated in court.

BELOW IS A PREVIOUS STORY FROM THE ASSOCIATED PRESS:

A witness told grand jurors investigating an alleged "pay-to-play" culture at the Pennsylvania Turnpike Commission that the agency, awash in toll-payers' money, is like the Mesopotamia River.

"All of the animals come and drink there," the grand jury report quoted the unnamed witness as saying. "If you were an engineering firm or a law firm or a consulting firm or whatever, you go to the turnpike because that is where the money is."

On Wednesday, a former state senator, three former top Pennsylvania Turnpike Commission officials and two businessmen were charged in a sweeping investigation that prosecutors said involved a long-running scheme in which contract-hungry vendors gave lavish gifts and political campaign contributions to improve their chances of landing lucrative contracts.

The group of former state officials used their extraordinary power over multimillion-dollar turnpike commission contracts both to enrich themselves, rig bids for favored businessmen and help sway political campaigns, Attorney General Kathleen Kane said. The largely-secret investigation that came to light Wednesday dates back to 2009 and involved hundreds of witnesses to crack a political and corrupt culture, she said.

"Evidence of secret gifts of cash, travel and entertainment and the payment of substantial political contributions to public officials and political organizations by private turnpike vendors and their consultants demonstrates that the turnpike operates under a pay-to-play system that is illegal and corrupt," Kane said.

The public, she said, "has lost untold millions of dollars" in inflated contracts, and she added that the "greatest improper influence" involved the turnpike's procurement process.

Charges were filed against retired state Senate Democratic floor leader Bob Mellow, currently jailed in a federal prison in South Carolina on unrelated corruption charges. Mellow, 70, was accused of helping supporters and contributors get business from the turnpike and pressuring turnpike staff to support him politically and raise campaign funds.

The investigation is continuing, but is restricted by an eight-year statute of limitations, Kane said.

Turnpike vendors named by the grand jury gave hundreds of thousands of dollars collectively in political campaign donations, while winning tens of millions of dollars in contracts over the past decade. Recipients of the campaign donations included former Philadelphia state Sen. Vincent J. Fumo, who is in federal prison on unrelated corruption charges, and former Gov. Ed Rendell.

The vendors also paid for gifts and entertainment worth tens of thousands of dollars, including trips to Paris and Vienna, tickets to professional baseball games, golf outings and expensive meals, some of which was not reported as required by the law, Kane said.

Business executives, including the two businessmen charged in the case, who participated in the pay-to-play system were rewarded with multimillion-dollar contracts, authorities said.

"The reason they made these contributions and provided these gifts (is) because they knew that was the way they would get these contracts," said state police Commissioner Frank Noonan.

Companies identified by the grand jury, but whose executives were not charged with wrongdoing, included engineering firms, transportation planning and design firms and a major bond underwriter.

Kane said the selection and recommendation of turnpike vendors followed what witnesses identified as a 60-40 rule that split up contracts among firms favored by Republicans and Democrats: 60 percent of the turnpike contracts went to the "majority party" and 40 percent went to the "minority party."

The governor appoints turnpike commissioners. Traditionally, three of the five turnpike commissioners are from the governor's political party, while the other two are from the other political party. Each must be confirmed by a two-thirds majority of the state Senate, helping give senators influence there.

A key witness who testified under grant of immunity was Tony Lepore, chief of staff to Mellow and to the current Democratic floor leader, Sen. Jay Costa of Allegheny County.

"Lepore explained that Senate officials would learn of work becoming available at the turnpike and would call ... Brimmeier and tell him which firm, vendor or consultant they wanted to steer turnpike work to," the grand jury wrote in an 88-page presentment released with the charges. "Generally, their requests were honored."

The other defendants were the turnpike's former chief operating officer George Hatalowich, 47; Dennis Miller, 51, a former vice president of information technology firm Ciber; and vendor consultant and registered lobbyist Jeffrey Suzenski, 63.

Miller, Rubin, Hatalowich and Suzenski were arraigned Wednesday and released on $100,000 unsecured bail. Brimmeier was due in court Thursday. Arrangement was pending for Mellow.

The men either declined comment or could not be reached Wednesday. Miller's lawyer said his client has cooperated fully with the grand jury investigation and will fight the charges.

The grand jury issued a separate report for two former turnpike commission employees.

Raymond Zajicek, 67, described as a close associate of Brimmeier and now retired from his $110,000-a-year job as fare collection operations manager, allegedly performed personal errands regularly on state time and occasionally made political fundraising calls during the work day or requested turnpike employees to perform political activities.

Melvin Shelton, 81, "held himself out to be a 'labor relations specialist'" but acted more like a Democratic party functionary, the grand jury said. He allegedly pressured officials to rehire fired employees who were registered Democrats by emphasizing his contacts with an unnamed Philadelphia congressman and with Rubin.

The turnpike figured tangentially in the federal criminal case against Fumo, who was convicted in 2009. Fumo is not identified by name in the jury report, but as Senator No. 6 he is described as having a powerful influence over the turnpike.

Political donations from turnpike vendors were directed to him and other senators of both parties who had sway over the turnpike commission, the report said.

Rendell ousted Rubin in March 2009, citing what he called "overwhelming" evidence in Fumo's trial testimony that Rubin had been paid $150,000 for a no-work job for the Appropriations Committee under Fumo.

Rendell also was not named, but it is clear he is referred to in the grand jury report as Gubernatorial Candidate No. 1, for whom Brimmeier and Hatalowich were allegedly collecting political donations from vendors. Rendell said Wednesday that he had not read the indictment and was unaware of any inappropriate activity.